WO2021090778A1 - Sagger and method for producing same - Google Patents

Sagger and method for producing same Download PDF

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Publication number
WO2021090778A1
WO2021090778A1 PCT/JP2020/040934 JP2020040934W WO2021090778A1 WO 2021090778 A1 WO2021090778 A1 WO 2021090778A1 JP 2020040934 W JP2020040934 W JP 2020040934W WO 2021090778 A1 WO2021090778 A1 WO 2021090778A1
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WO
WIPO (PCT)
Prior art keywords
protective layer
saggar
positive electrode
sno
electrode material
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PCT/JP2020/040934
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French (fr)
Japanese (ja)
Inventor
小川　修平
宮川　直通
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Ａｇｃ株式会社
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Priority to JP2021554924A priority Critical patent/JPWO2021090778A1/ja
Publication of WO2021090778A1 publication Critical patent/WO2021090778A1/en

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    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/64—Burning or sintering processes
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/80—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone of only ceramics
    • C04B41/81—Coating or impregnation
    • C04B41/85—Coating or impregnation with inorganic materials
    • C04B41/87—Ceramics
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D3/00—Charging; Discharging; Manipulation of charge
    • F27D3/12—Travelling or movable supports or containers for the charge
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a saggar and a method for producing the same.
  • Lithium-ion secondary batteries are often used as a power source for portable electronic devices such as mobile phones and notebook personal computers.
  • Lithium-containing composite oxides for example, lithium cobalt composite oxide, lithium nickel composite oxide, lithium manganese composite oxide, lithium manganese cobalt composite oxide, lithium nickel cobalt composite oxide
  • Lithium-containing composite oxides are used as the positive electrode active material of the lithium ion secondary battery. Things, etc. are included.
  • the raw material of the positive electrode active material (hereinafter referred to as lithium ion positive electrode material) is fired in a roller harsher kiln, which is a continuous furnace using a raggar.
  • a roller harsher kiln which is a continuous furnace using a raggar.
  • composite materials such as mullite and mullite / cordierite have been mainly used as the material of the saggar.
  • Patent Document 1 a bowl containing a spinel-based or magnesia-based material using a basic material.
  • Document 2 a bowl containing a spinel-based or magnesia-based material using a basic material.
  • lithium and cobalt contained in the lithium ion positive electrode material diffuse into the pot and react with the constituents of the pot body, and the reaction product deteriorates the durability of the pot. The life is shortened, and the recovery efficiency of the lithium ion positive electrode material is lowered.
  • the saggar is required to have good releasability from the lithium ion positive electrode active material obtained after firing the lithium ion positive electrode material. If the peelability is poor, the recovery efficiency of the lithium ion positive electrode active material from the pot after firing is lowered, and the reaction product of lithium or cobalt and the constituent components of the pot body is mixed in the lithium ion positive electrode active material. , Deteriorate performance.
  • the present invention provides a saggar having excellent corrosion resistance against diffusion of lithium and cobalt during firing of a lithium ion positive electrode material, and excellent peelability from a fired product and heat impact resistance. The purpose.
  • the present inventors have found that the above problems can be solved by providing a protective layer containing at least 70% by mass or more of SnO 2 on the surface of the bowl body made of an amorphous refractory that comes into contact with the lithium ion positive electrode material. , The present invention has been completed.
  • the present invention is as follows. 1.
  • a saggar that includes a saggar body and a protective layer that covers the surface of the saggar body.
  • the protective layer is a saggar containing at least 70% by mass or more of SnO 2.
  • a pot for firing a lithium ion positive electrode material comprising a pot body and a protective layer covering a surface of the pot body that comes into contact with the lithium ion positive electrode material.
  • the protective layer is a saggar containing at least 70% by mass or more of SnO 2.
  • 3. The saggar according to 1 or 2 above, wherein the protective layer contains ZrO 2. 4.
  • a method for producing a lithium-ion positive electrode material firing sack which comprises preparing a sack body and providing a protective layer on the surface of the sack body that comes into contact with the lithium-ion positive electrode material.
  • the protective layer containing at least 70% by mass or more of SnO 2 covers the surface of the saggar body in contact with the lithium ion positive electrode material. It is provided.
  • the protective layer suppresses the reaction between lithium and cobalt contained in the lithium ion positive electrode material and the constituent components of the saggar body, and is excellent in corrosion resistance and thermal shock resistance.
  • the protective layer has good releasability from the lithium ion positive electrode active material, the recovery efficiency of the lithium ion positive electrode material can be improved, and the manufacturing cost can be reduced. ..
  • FIG. 1 is a cross-sectional view showing an embodiment of the bowl of the present invention.
  • FIG. 2 is a diagram showing the surface of the saggar of Example 1 in which the lithium ion positive electrode material is fired once.
  • FIG. 3 is a diagram showing the surface of the saggar of Example 3 in which the lithium ion positive electrode material is fired once.
  • FIG. 4 is a diagram showing the surface of the saggar of Example 4 in which the lithium ion positive electrode material is fired once.
  • FIG. 5 is a diagram showing the surface of the saggar of Example 5 in which the lithium ion positive electrode material is fired once.
  • 6 (a) and 6 (b) are views showing the surface of a substrate having the same composition as the protective layer of Example 10 in which the lithium ion positive electrode material is fired once.
  • FIG. 1 is a side sectional view of a saggar 1 for firing a lithium ion positive electrode material according to the present invention.
  • the saggar 1 for firing a lithium ion positive electrode material includes a saggar body 2 and a protective layer 3 that covers a surface of the saggar body 2 that comes into contact with the lithium ion positive electrode material.
  • the protective layer 3 covers the entire surface of the inner surface 21 including the bottom portion 211 and the wall surface 212 of the inner surface 21 of the saggar body 2.
  • a refractory is a material that has high temperature resistance, and is roughly divided into a standard refractory and an amorphous refractory.
  • the standard refractory is a general term for refractories that have been molded and fired in advance
  • the amorphous refractory is a general term for refractories in the form of powder or kneaded soil.
  • the saggar body 2 is made of an amorphous refractory material.
  • the amorphous refractory used for the bowl body 2 is not particularly limited, but for example, zirconia, zircone, mullite, cordierite, mullite-corgerite, chromia, magnesia raw material and chromium iron ore are the main bones.
  • ZrSiO 4 reacts with SnO 2 contained in the protective layer 3 at the interface between the saggar body 2 and the protective layer 3 to form a silica layer. This is preferable because the adhesion between the protective layer 3 and the saggar body 2 can be improved.
  • the porosity of the saggar body 2 is preferably 30 Vol% or less, more preferably 26 Vol% or less, further preferably 22 Vol% or less, and particularly preferably 20 Vol% or less.
  • the porosity of the saggar body 1 is preferably 3 Vol% or more, more preferably 8 Vol% or more, further preferably 13 Vol% or more, and particularly preferably 15 Vol% or more.
  • the porosity of the saggar is 3 Vol% or more, the heat impact resistance can be enhanced and the weight of the saggar can be reduced.
  • the bulk specific gravity of the bowl body 2 is preferably 1.8 g / cm 3 or more and 5.0 g / cm 3 or less, more preferably 2.0 g / cm 3 or more and 4.8 g / cm 3 or less, and further. It is preferably 2.2 g / cm 3 or more and 4.6 g / cm 3 or less.
  • the smaller the bulk specific gravity the smaller the heat capacity and the higher the thermal shock resistance.
  • the bulk specific gravity of the saggar body 1 is 1.8 g / cm 3 or more, mechanical characteristics that can withstand use as the saggar body can be realized.
  • the bulk specific gravity of the saggar body 1 is 4.9 g / cm 3 or less, the heat capacity can be reduced, the electric energy can be reduced, and the thermal shock resistance can be improved.
  • the coefficient of thermal expansion of the saggar body 2 is preferably 0.1 ⁇ 10 -6 / ° C or higher and 4.8 ⁇ 10 -6 / ° C or lower, more preferably 1.5 ⁇ 10 -6 / ° C or higher 4 It is .6 ⁇ 10 -6 / °C or less, more preferably 3.0 ⁇ 10 -6 / °C or more and 4.4 ⁇ 10 -6 / °C or less, and particularly preferably 3.8 ⁇ 10 -6 / °C.
  • the above is 4.3 ⁇ 10 -6 / ° C or lower, and more preferably 4.1 ⁇ 10 -6 / ° C or higher and 4.25 ⁇ 10 -6 / ° C or lower.
  • the thermal expansion coefficient of the saggar body 1 By setting the thermal expansion coefficient of the saggar body 1 within the above range, the thermal impact resistance can be improved and the stress generated on the protective layer due to the difference in the coefficient of thermal expansion from the protective layer can be suppressed, so that the life of the saggar can be extended. Can be extended.
  • the coefficient of thermal expansion is measured at room temperature to 1100 ° C. according to JIS R2207-2.
  • the shape and dimensions of the saggar body 2 are not particularly limited, and a suitable form can be appropriately selected as long as it can accommodate a lithium ion positive electrode material and can be fired.
  • the protective layer 3 contains at least 70% by mass or more of SnO 2 .
  • the protective layer 3 can suppress the reaction between lithium and cobalt contained in the lithium ion positive electrode material and the constituent components of the saggar body, and can improve corrosion resistance and thermal shock resistance.
  • the protective layer 3 can enhance the releasability from the lithium ion positive electrode active material and improve the recovery efficiency of the lithium ion positive electrode material.
  • the content of SnO 2 in the protective layer 3 is preferably 80% by mass or more, more preferably 90% by mass or more, and particularly preferably 95% by mass or more, with the entire protective layer as 100% by mass.
  • the protective layer 3 contains 70% by mass or more of SnO 2 , it is possible to exhibit excellent corrosion resistance against the diffusion of lithium and cobalt contained in the lithium ion positive electrode material when firing the lithium ion positive electrode material.
  • the protective layer 3 preferably contains ZrO 2. By containing ZrO 2 in the protective layer 3, volatilization of SnO 2 can be suppressed.
  • the protective layer 3 preferably contains SiO 2 in addition to ZrO 2. In addition to ZrO 2, by containing SiO 2, it can exhibit excellent volatilization suppressing effect of SnO 2 from the initial stage after the start volatilization, further to enhance the adhesion between the sagger body and the protective layer it can.
  • the total content of SnO 2 , ZrO 2 and SiO 2 in the protective layer 3 is preferably 70% by mass or more, more preferably 85% by mass or more, still more preferably 95% by mass or more, and in particular. It is preferably 98% by mass or more.
  • the upper limit is not particularly limited, but is typically 99.5% by mass or less.
  • the content ratio of the total amount of ZrO 2 and SiO 2 is preferably 2 to 50 mol%, more preferably 4 with respect to the total content of SnO 2 , ZrO 2 and SiO 2 (100 mol%). It is ⁇ 35 mol%, more preferably 6-24 mol%, and particularly preferably 8-15 mol%.
  • the content ratio of the total amount of ZrO 2 and SiO 2 is 2 mol% or more with respect to the total content of SnO 2 , ZrO 2 and SiO 2 (100 mol%), the effect of suppressing the volatilization of SnO 2 is achieved. Is sufficiently obtained.
  • the content ratio is 50 mol% or less, the effect of improving the corrosion resistance by SnO 2 can be sufficiently obtained.
  • SnO 2 , SiO 2 and ZrO 2 in the protective layer 3 from the viewpoint of suppressing the volatilization of SnO 2 in a high temperature field from an early stage and exhibiting the excellent corrosion resistance of SnO 2 against lithium and cobalt.
  • the effect of suppressing volatilization by ZrO 2 and ZrSiO 4 can be sufficiently obtained. Further, by setting the content ratio of SiO 2 to 1 mol% or more, the effect of suppressing volatilization by ZrO 2 and ZrSiO 4 can be sufficiently obtained.
  • the content ratio of ZrO 2 is preferably in the range of 1 to 12 mol% with respect to the total content of SnO 2 , ZrO 2 and SiO 2.
  • the content ratio of SiO 2 is preferably in the range of 1 to 12 mol% with respect to the total content of SnO 2 , ZrO 2 and SiO 2. Therefore, the content ratio of SnO 2 is preferably in the range of 76 to 98 mol% with respect to the total content of SnO 2 , ZrO 2 and SiO 2.
  • the effect of suppressing volatilization by ZrO 2 and ZrSiO 4 and the effect of improving corrosion resistance by SnO 2 are sufficient. Obtained in. Further, the adhesion between the saggar body and the protective layer can be improved.
  • SnO 2 , ZrO 2 and SiO 2 in the refractory composition depend on the sintering conditions to be actually treated.
  • the blending amount of the above may be adjusted.
  • the other components described above are not particularly limited as long as they do not impair the characteristics of the refractory of the present invention, and examples thereof include known components used in tin oxide refractories.
  • Other components include, for example, Al 2 O 3 , SiO 2 , CaO, MgO, Li 2 O, CuO, Cu 2 O, ZnO, HfO 2 , Y 2 O 3 , ZnO, Mn 2 O 3 , CoO, TiO. 2 , Ta 2 O 5 , CeO 2 , Sb 2 O 3 , Nb 2 O 5 , Bi 2 O 3 , UO 2 , HfO 2 and other oxides can be mentioned.
  • the protective layer 3 preferably does not contain Fe from the viewpoint of corrosion resistance to lithium and cobalt.
  • the Fe content in the protective layer 3 is preferably 0.5% by mass or less, more preferably 0.3% by mass or less, still more preferably 0.05% by mass or less.
  • the coefficient of thermal expansion of the protective layer 3 is preferably 3.5 ⁇ 10-6 / ° C. or higher and 5.0 ⁇ 10-6 / ° C. or lower, more preferably 3.7 ⁇ 10-6 / ° C. or higher and 4.7. ⁇ 10 -6 / ° C or lower, more preferably 3.95 ⁇ 10 -6 / ° C or higher and 4.5 ⁇ 10 -6 / ° C or lower, and particularly preferably 4.1 ⁇ 10 -6 / ° C or higher 4 .3 x 10-6 / ° C or less.
  • the method for manufacturing a pot for firing a lithium ion positive electrode material of the present invention includes a step of preparing a pot body 2 and a step of providing a protective layer 3 on a surface of the pot body 2 in contact with the positive electrode material.
  • ⁇ Process of preparing the saggar body As a means for preparing the saggar body 2, an appropriate amount of binder material and water are added to the raw material of the refractory, kneaded, molded (for example, pressure molding by a friction press or the like), and dried (for example, pressure molding by a friction press or the like). After air-drying), it is fired. The firing temperature and time can be set as appropriate.
  • the means for providing the protective layer 3 on the saggar body 2 is not particularly limited, and examples thereof include coating, sintering, and pasting.
  • the means for providing the protective layer 3 on the pot body 2 by coating is not particularly limited, and examples thereof include coating, spray coating, and thermal spraying. Specifically, for example, a material containing at least 70% by mass or more of SnO 2 is dispersed in a solvent such as pure water or ion-exchanged water to form a slurry, and then the inner surface of the saggar body 2 that comes into contact with the positive electrode material. Is spray coated to form the protective layer 3. Then it is fired at 1200 ° C. for 5 hours.
  • the thickness of the protective layer 3 formed by the coating is preferably 1 mm or less, more preferably 800 ⁇ m or less, and more preferably 500 ⁇ m or less in order to suppress cracking due to the difference in thermal expansion coefficient from the saggar body 2. Further, from the viewpoint of improving durability, it is preferably 1 ⁇ m or more, more preferably 10 ⁇ m or more, still more preferably 50 ⁇ m or more, and particularly preferably 100 ⁇ m or more.
  • a method of simultaneously sintering the material of the protective layer 3 at the time of sintering for producing the saggar main body 2 can be mentioned. Specifically, for example, after pouring the material of the saggar body 2 into the mold for the saggar body, the material of the protective layer 3 containing at least 70% by mass or more of SnO 2 is poured before firing the saggar. The pot body 2 and the protective layer 3 are sintered at the same time. By simultaneously sintering the saggar body 2 and the protective layer 3, the saggar body 2 and the protective layer 3 can be more firmly fixed to each other, and the durability can be improved.
  • the material of the protective layer 3 preferably contains ZrSiO 4 in addition to SnO 2.
  • ZrSiO 4 is in addition to SnO 2.
  • SiO 2 is generated and ZrO 2 is in a solid solution state in SnO 2.
  • the particles forming the protective layer are bonded to each other by SiO 2 , and the adhesion between the saggar body and the protective layer becomes stronger.
  • ZrSiO 4 exceeding the solid solution limit is contained, ZrSiO 4 remains as an unreacted component.
  • the particles forming the protective layer are bonded to each other at SiO 2 and ZrSiO 4 , and the adhesion between the saggar body and the protective layer becomes stronger. Also by SiO 2 and / or ZrSiO 4 are present in the grain boundary of the SnO 2, volatilization of SnO 2 can be effectively suppressed.
  • the thickness of the protective layer 3 formed by sintering is preferably 10 mm or less, more preferably 5 mm or less. It is particularly preferably 3 mm or less from the viewpoint of suppressing cost and mass.
  • SnO 2 contained in the material of the protective layer 3 is preferably applied as particles, and the particle size of the particles is, for example, a maximum particle size of 1 to 3 mm, and coarse particles, medium particles, fine particles, fine particles and particles. It is preferable to combine particles having different diameters and adjust appropriately. Further, for the purpose of imparting durability to the protective layer 3, in addition to the above-mentioned coarse particles, medium particles, fine particles, and fine particles, for example, SnO 2 having a particle size of 3 to 50 ⁇ m may be combined.
  • the particle size refers to a value measured according to JIS R2552 (1977).
  • SnO 2 a product after using a refractory material, a waste material of a refractory material, or the like may be crushed to adjust the particle size.
  • the protective layer 3 As a means for providing the protective layer 3 on the saggar main body 2 by sticking, for example, after forming an adhesive layer on the forming surface of the protective layer 3 of the saggar main body 2, the protective layer 3 is pressed against the adhesive layer.
  • the adhesive include glass, alumina-based adhesives, zirconia-based adhesives, and metals such as silicon.
  • the adhesive is glass, it is protected by forming an adhesive layer containing fine particles of glass on the forming surface of the protective layer 3 of the saggar body 2 and then baking and melting the glass.
  • the layer 3 and the saggar body 2 are integrated.
  • the thickness of the adhesive layer is usually preferably 5 to 500 ⁇ m, more preferably 10 to 200 ⁇ m.
  • the thickness of the protective layer 3 is preferably 10 mm or less, more preferably 5 mm or less. From the viewpoint of suppressing cost and mass, it is particularly preferably 3 mm or less, and particularly preferably 1 mm or less.
  • the surface of the pot body 2 in contact with the positive electrode material is covered with a protective layer 3 containing at least 70% by mass or more of SnO 2.
  • the protective layer 3 suppresses the reaction between lithium and cobalt contained in the lithium ion positive electrode material and the constituent components of the pot body 2, so that the lithium ion positive electrode material firing pot has excellent corrosion resistance and thermal shock resistance.
  • the raw materials of the saggar body are mixed so as to have the composition shown in Table 1, filled in a saggar mold, and pressure-molded at a molding pressure of 44 MPa using a friction press to obtain the dimensions and outer shape after firing.
  • the saggar body was molded so as to have a plate shape having a size and an outer shape of 150 mm ⁇ 150 mm ⁇ 10 mm (height).
  • the molded product was fired in a firing furnace through a natural drying step and an end face finishing step to obtain a saggar body substrate.
  • Examples 1 to 5 are comparative examples in which the protective layer was not formed on the saggar body substrate.
  • the porosity, density, and coefficient of thermal expansion of the obtained saggar body substrate were measured. Porosity was measured according to JIS R2205 (1992). The coefficient of thermal expansion was measured at room temperature to 1100 ° C. according to JIS R2207-2 (2007). Bulk density and porosity were measured by JIS R2205 (1992).
  • the particle size and ratio are 45% by mass for 0.05 mm, 20% by mass for 0.01 mm, and 13% by mass for 0.003 mm. , 0.00087 mm is 22% by mass.
  • SnO 2 in the protective layer in Examples 12 to 14 those having a particle size of 0.003 mm were used.
  • the particle size and ratio are 27% by mass for 1.7 mm, 22% by mass for 0.68 mm, 35% by mass for 0.24 mm, and 16% by mass for 0.003 mm. Something was used.
  • the thickness of the protective layer formed as described above was measured.
  • the porosity, bulk density, and coefficient of thermal expansion were measured by preparing a sample having a protective layer thickness of 5 mm and using a measurement sample cut out from the protective layer. Porosity was measured according to JIS R2205 (1992). The coefficient of thermal expansion was measured at room temperature to 1100 ° C. according to JIS R2207-2 (2007).
  • ⁇ Sintering of lithium ion positive electrode material> The substrate prepared as described above was tapped with 15 g of a lithium ion positive electrode material (10 g of lithium carbonate and 5 g of cobalt oxide) so as to have an area of 50 mm in diameter. After raising the temperature to 1050 ° C. over 4 hours, the temperature was maintained for 10 hours, and the temperature was lowered to room temperature over 6 hours.
  • the amount of adhesion was measured by turning the substrate over after firing the lithium ion positive electrode material and allowing it to stand still for 5 seconds, and then measuring the amount of adhesion of the lithium ion positive electrode material.
  • FIGS. 6A and 6B show the results of sintering a lithium ion positive electrode material on a substrate (thickness 20 mm) having the same protective layer composition as in Example 10.
  • Examples 1 to 5, 7 and 8 are comparative examples, and examples 6, 9 to 27 are examples.
  • a protective layer containing at least 70% by mass or more of SnO 2 was provided to cover the surface of the saggar body in contact with the positive electrode material. It had good releasability from the active material, and was excellent in corrosion resistance and thermal shock resistance. Further, from the results of Examples 6 and 12 in which the protective layer was formed by the coating, when the protective layer was formed by the coating, the thickness of the protective layer suppressed cracking due to the difference in the coefficient of thermal expansion from the saggar body. It was found that it is preferably 1 mm or less.
  • FIGS. 6A and 6B as a result of sintering the lithium ion positive electrode material on the substrate containing at least 70% by mass or more of SnO 2, the contact surface of the substrate with the lithium ion positive electrode material.
  • the lithium ion positive electrode material was not adhered at all, and when it was tilted, it slipped off due to its own weight, and the formation of a reaction layer was hardly observed.
  • FIGS. 2 to 5 show the results of sintering the lithium ion positive electrode material on a substrate that does not form a protective layer containing at least 70% by mass or more of SnO 2.
  • FIG. 1 shows the results of sintering the lithium ion positive electrode material on a substrate that does not form a protective layer containing at least 70% by mass or more of SnO 2.

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Abstract

The purpose of the present invention is to provide a sagger that has excellent corrosion resistance with respect to diffusion of lithium and cobalt during firing of lithium ion positive electrode materials, excellent releasability from the fired product, and excellent thermal shock resistance. Provided are a sagger and a method for producing the same. The sagger has a sagger body and a protective layer for covering the surface of the sagger body. The protective layer contains at least 70 mass% of SnO2.

Description

匣鉢及びその製造方法Saggar and its manufacturing method
　本発明は、匣鉢及びその製造方法に関する。 The present invention relates to a saggar and a method for producing the same.
　リチウムイオン二次電池は、携帯電話機やノート型パーソナルコンピュータ等のポータブル型電子機器の電源として多く使用されている。リチウムイオン二次電池の正極活物質には、リチウム含有複合酸化物（例えば、リチウムコバルト複合酸化物、リチウムニッケル複合酸化物、リチウムマンガン複合酸化物、リチウムマンガンコバルト複合酸化物、リチウムニッケルコバルト複合酸化物等）が含まれている。 Lithium-ion secondary batteries are often used as a power source for portable electronic devices such as mobile phones and notebook personal computers. Lithium-containing composite oxides (for example, lithium cobalt composite oxide, lithium nickel composite oxide, lithium manganese composite oxide, lithium manganese cobalt composite oxide, lithium nickel cobalt composite oxide) are used as the positive electrode active material of the lithium ion secondary battery. Things, etc.) are included.
　一般的に、前記正極活物質の原料（以下、リチウムイオン正極材と称する）は、匣鉢を用いた連続炉であるローラーハースキルン炉によって焼成される。従来、匣鉢の材質として、ムライト及びムライト・コージェライト等の複合材料が主に用いられている。 Generally, the raw material of the positive electrode active material (hereinafter referred to as lithium ion positive electrode material) is fired in a roller harsher kiln, which is a continuous furnace using a raggar. Conventionally, composite materials such as mullite and mullite / cordierite have been mainly used as the material of the saggar.
　また、リチウムイオン正極材の焼成時に発生するアルカリ蒸気に対する耐食性を向上させるために、塩基性材料を用いたスピネル系やマグネシア系等の材質を含む匣鉢が開発されている（特許文献１及び特許文献２）。 Further, in order to improve the corrosion resistance to the alkaline vapor generated at the time of firing the lithium ion positive electrode material, a bowl containing a spinel-based or magnesia-based material using a basic material has been developed (Patent Document 1 and Patent). Document 2).
日本国特許第３３５２２１０号公報Japanese Patent No. 3352210 日本国特開２００３－１６５７６７号公報Japanese Patent Application Laid-Open No. 2003-165767
　リチウムイオン正極材の焼成時に、該リチウムイオン正極材に含まれるリチウムやコバルトが匣鉢に拡散し、匣鉢本体の構成成分と反応して、当該反応物により匣鉢の耐久性が劣化して寿命が短縮されるとともに、該リチウムイオン正極材の回収効率が低下する。 When the lithium ion positive electrode material is fired, lithium and cobalt contained in the lithium ion positive electrode material diffuse into the pot and react with the constituents of the pot body, and the reaction product deteriorates the durability of the pot. The life is shortened, and the recovery efficiency of the lithium ion positive electrode material is lowered.
　一方で、特許文献１及び特許文献２に記載の匣鉢のようにスピネル系やマグネシア系の含有率が高いものであると、匣鉢の耐食性は高まるものの、熱膨張率が高くなる。通常、正極活物質の製造時における焼成後の降温工程では、製造効率を高めるために、匣鉢及び焼成物が強制的に冷却される。そのため、匣鉢の熱膨張率が高くなると、降温工程時にクラックが発生して耐熱衝撃性が低下し、使用上における破損や亀裂につながる。 On the other hand, if the content of the spinel-based or magnesia-based gasgar is high as in the pots described in Patent Document 1 and Patent Document 2, the corrosion resistance of the pot is increased, but the coefficient of thermal expansion is high. Usually, in the temperature lowering step after firing during the production of the positive electrode active material, the saggar and the fired product are forcibly cooled in order to improve the production efficiency. Therefore, when the coefficient of thermal expansion of the pot becomes high, cracks are generated during the temperature lowering process and the heat impact resistance is lowered, which leads to breakage or cracks in use.
　また、匣鉢にはリチウムイオン正極材の焼成後に得られたリチウムイオン正極活物質との剥離性が良好なものが求められる。該剥離性が悪いと、焼成後における匣鉢からのリチウムイオン正極活物質の回収効率が低下して、リチウムやコバルトと匣鉢本体の構成成分との反応物がリチウムイオン正極活物質に混入し、性能を低下させる。 Further, the saggar is required to have good releasability from the lithium ion positive electrode active material obtained after firing the lithium ion positive electrode material. If the peelability is poor, the recovery efficiency of the lithium ion positive electrode active material from the pot after firing is lowered, and the reaction product of lithium or cobalt and the constituent components of the pot body is mixed in the lithium ion positive electrode active material. , Deteriorate performance.
　したがって、本発明は、リチウムイオン正極材の焼成時のリチウムやコバルトの拡散に対して優れた耐食性を有し、焼成物との剥離性及び耐熱衝撃性に優れた、匣鉢を提供することを目的とする。 Therefore, the present invention provides a saggar having excellent corrosion resistance against diffusion of lithium and cobalt during firing of a lithium ion positive electrode material, and excellent peelability from a fired product and heat impact resistance. The purpose.
　本発明者らは、不定形耐火物からなる匣鉢本体のリチウムイオン正極材と接触する面に、少なくとも７０質量％以上のＳｎＯ２を含有する保護層を設けることにより上記課題を解決できることを見出し、本発明を完成させた。 The present inventors have found that the above problems can be solved by providing a protective layer containing at least 70% by mass or more of SnO 2 on the surface of the bowl body made of an amorphous refractory that comes into contact with the lithium ion positive electrode material. , The present invention has been completed.
　すなわち、本発明は以下のとおりである。
１．匣鉢本体と、前記匣鉢本体の表面を被覆する保護層と、を備える匣鉢であって、
　前記保護層は少なくとも７０質量％以上のＳｎＯ２を含む、匣鉢。
２．匣鉢本体と、前記匣鉢本体のリチウムイオン正極材と接触する面を被覆する保護層と、を備えるリチウムイオン正極材焼成用匣鉢であって、
　前記保護層は少なくとも７０質量％以上のＳｎＯ２を含む、匣鉢。
３．前記保護層がＺｒＯ２を含む、前記１または２に記載の匣鉢。
４．前記保護層がＳｉＯ２を含む、前記１～３のいずれか１に記載の匣鉢。
５．前記保護層におけるＳｎＯ２、ＺｒＯ２およびＳｉＯ２の含有量の合量に対して、ＺｒＯ２およびＳｉＯ２の合量の含有割合が２～５０モル％である、前記１～４のいずれか１に記載の匣鉢。
６．前記匣鉢本体がジルコン質不定形耐火物からなる前記１～５のいずれか１に記載の匣鉢。
７．前記匣鉢本体の気孔率が３０Ｖｏｌ％以下である、前記１～６のいずれか１に記載の匣鉢。
８．前記匣鉢本体のかさ比重が１．８ｇ／ｃｍ３以上５．０ｇ／ｃｍ３以下である、前記１～７のいずれか１に記載の匣鉢。
９．前記匣鉢本体の熱膨張係数が０．１×１０－６／℃以上４．８×１０－６／℃以下である、前記１～８のいずれか１に記載の匣鉢。
１０．前記保護層の熱膨張係数が３．５×１０－６／℃以上５．０×１０－６／℃以下である、前記１～９のいずれか１に記載の匣鉢。
１１．匣鉢本体を準備し、前記匣鉢本体のリチウムイオン正極材と接触する面に保護層を設けることを含むリチウムイオン正極材焼成用匣鉢の製造方法であって、
　前記保護層が少なくとも７０質量％以上のＳｎＯ２を含むリチウムイオン正極材焼成用匣鉢の製造方法。 That is, the present invention is as follows.
1. 1. A saggar that includes a saggar body and a protective layer that covers the surface of the saggar body.
The protective layer is a saggar containing at least 70% by mass or more of SnO 2.
2. A pot for firing a lithium ion positive electrode material, comprising a pot body and a protective layer covering a surface of the pot body that comes into contact with the lithium ion positive electrode material.
The protective layer is a saggar containing at least 70% by mass or more of SnO 2.
3. 3. The saggar according to 1 or 2 above, wherein the protective layer contains ZrO 2.
4. The saggar according to any one of 1 to 3 above, wherein the protective layer contains SiO 2.
5. Any one of 1 to 4 above, wherein the content ratio of the total amount of ZrO 2 and SiO 2 is 2 to 50 mol% with respect to the total content of SnO 2 , ZrO 2 and SiO 2 in the protective layer. The bowl described in.
6. The saggar according to any one of 1 to 5 above, wherein the saggar body is made of a zircon amorphous refractory.
7. The saggar according to any one of 1 to 6 above, wherein the saggar body has a porosity of 30 Vol% or less.
8. The saggar according to any one of 1 to 7, wherein the saggar body has a bulk specific gravity of 1.8 g / cm 3 or more and 5.0 g / cm 3 or less.
9. The pot according to any one of 1 to 8 above, wherein the coefficient of thermal expansion of the pot body is 0.1 × 10 -6 / ° C or higher and 4.8 × 10 -6 / ° C or lower.
10. The saggar according to any one of 1 to 9 above, wherein the coefficient of thermal expansion of the protective layer is 3.5 × 10 -6 / ° C. or higher and 5.0 × 10 -6 / ° C. or lower.
11. A method for producing a lithium-ion positive electrode material firing sack, which comprises preparing a sack body and providing a protective layer on the surface of the sack body that comes into contact with the lithium-ion positive electrode material.
A method for producing a saggar for firing a lithium ion positive electrode material, wherein the protective layer contains at least 70% by mass or more of SnO 2.
　本発明の匣鉢、特には、リチウムイオン正極材焼成用匣鉢は、少なくとも７０質量％以上のＳｎＯ２を含有する保護層が匣鉢本体のリチウムイオン正極材と接触する面を被覆するように設けられている。該保護層により、リチウムイオン正極材に含まれるリチウムやコバルトと匣鉢本体の構成成分との反応を抑制し、耐食性及び耐熱衝撃性に優れる。また、本発明のリチウムイオン正極材焼成用匣鉢は、該保護層により、リチウムイオン正極活物質との剥離性も良好であり、リチウムイオン正極材の回収効率を向上でき、製造コストを低減できる。 In the saggar of the present invention, particularly the saggar for firing the lithium ion positive electrode material, the protective layer containing at least 70% by mass or more of SnO 2 covers the surface of the saggar body in contact with the lithium ion positive electrode material. It is provided. The protective layer suppresses the reaction between lithium and cobalt contained in the lithium ion positive electrode material and the constituent components of the saggar body, and is excellent in corrosion resistance and thermal shock resistance. Further, in the lithium ion positive electrode material firing pot of the present invention, the protective layer has good releasability from the lithium ion positive electrode active material, the recovery efficiency of the lithium ion positive electrode material can be improved, and the manufacturing cost can be reduced. ..
図１は、本発明の匣鉢の一実施形態を示す断面図である。FIG. 1 is a cross-sectional view showing an embodiment of the bowl of the present invention. 図２は、リチウムイオン正極材を１回焼成した例１の匣鉢の表面を示す図である。FIG. 2 is a diagram showing the surface of the saggar of Example 1 in which the lithium ion positive electrode material is fired once. 図３は、リチウムイオン正極材を１回焼成した例３の匣鉢の表面を示す図である。FIG. 3 is a diagram showing the surface of the saggar of Example 3 in which the lithium ion positive electrode material is fired once. 図４は、リチウムイオン正極材を１回焼成した例４の匣鉢の表面を示す図である。FIG. 4 is a diagram showing the surface of the saggar of Example 4 in which the lithium ion positive electrode material is fired once. 図５は、リチウムイオン正極材を１回焼成した例５の匣鉢の表面を示す図である。FIG. 5 is a diagram showing the surface of the saggar of Example 5 in which the lithium ion positive electrode material is fired once. 図６（ａ）及び（ｂ）は、リチウムイオン正極材を１回焼成した例１０の保護層と同一の組成からなる基板の表面を示す図である。6 (a) and 6 (b) are views showing the surface of a substrate having the same composition as the protective layer of Example 10 in which the lithium ion positive electrode material is fired once.
　以下、本発明の実施形態について図面を用いて説明する。なお、本発明は以下の記述に限定されるものではなく、本発明の要旨を逸脱しない範囲において適宜変更可能である。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the following description, and can be appropriately modified without departing from the gist of the present invention.
＜リチウムイオン正極材焼成用匣鉢＞
　図１は、本発明に係るリチウムイオン正極材焼成用匣鉢１の側面断面図である。図１に示すように、リチウムイオン正極材焼成用匣鉢１は、匣鉢本体２と該匣鉢本体２のリチウムイオン正極材と接触する面を被覆する保護層３とを備えている。本実施形態では、保護層３は、匣鉢本体２の内側表面２１の底部２１１と壁面２１２からなる内側表面２１の全面を覆っている。 <Saggar for firing lithium-ion positive electrode material>
FIG. 1 is a side sectional view of a saggar 1 for firing a lithium ion positive electrode material according to the present invention. As shown in FIG. 1, the saggar 1 for firing a lithium ion positive electrode material includes a saggar body 2 and a protective layer 3 that covers a surface of the saggar body 2 that comes into contact with the lithium ion positive electrode material. In the present embodiment, the protective layer 3 covers the entire surface of the inner surface 21 including the bottom portion 211 and the wall surface 212 of the inner surface 21 of the saggar body 2.
　耐火物とは高温耐性を有する素材をいい、定形耐火物と不定形耐火物とに大別される。定形耐火物とは予め成形・焼成された耐火物の総称であり、不定形耐火物とは粉粒体または練り土状の耐火物の総称である。 A refractory is a material that has high temperature resistance, and is roughly divided into a standard refractory and an amorphous refractory. The standard refractory is a general term for refractories that have been molded and fired in advance, and the amorphous refractory is a general term for refractories in the form of powder or kneaded soil.
＜＜匣鉢本体＞＞
　匣鉢本体２は、不定形耐火物からなる。匣鉢本体２に用いる不定形耐火物としては特に限定されないが、例えば、ジルコニア質、ジルコン質、ムライト質、コージェライト質、ムライト－コージェライト質、クロミア質、マグネシア質原料とクロム鉄鉱を主骨材とするマグネシア－クロム質、マグネシア（ＭｇＯ）とスピネル（ＭｇＡｌ２Ｏ４）の固溶体からなるマグネシア－スピネル質、マグネシア（ＭｇＯ）－チタニア（ＴｉＯ２）－アルミナ（Ａｌ２Ｏ３）質またはマグネシア－スピネル－アルミナ－チタニア質の耐火物が挙げられる。特に、匣鉢本体２がジルコン質不定形耐火物であると、匣鉢本体２と保護層３との界面においてＺｒＳｉＯ４と保護層３に含まれるＳｎＯ２とが反応してシリカ層を生成し、保護層３と匣鉢本体２との密着性を向上できるため好ましい。 << Saggar body >>
The saggar body 2 is made of an amorphous refractory material. The amorphous refractory used for the bowl body 2 is not particularly limited, but for example, zirconia, zircone, mullite, cordierite, mullite-corgerite, chromia, magnesia raw material and chromium iron ore are the main bones. Magnesia-chromic material, magnesia-spinel material consisting of a solid solution of magnesia (MgO) and spinel (MgAl 2 O 4 ), magnesia (MgO) -titania (TIO 2 ) -alumina (Al 2 O 3 ) quality or magnesia -Spinel-Alumina-Titania refractories can be mentioned. In particular, when the saggar body 2 is a zircon amorphous refractory, ZrSiO 4 reacts with SnO 2 contained in the protective layer 3 at the interface between the saggar body 2 and the protective layer 3 to form a silica layer. This is preferable because the adhesion between the protective layer 3 and the saggar body 2 can be improved.
　匣鉢本体２の気孔率は３０Ｖｏｌ％以下が好ましく、より好ましくは２６Ｖｏｌ％以下であり、さらに好ましくは２２Ｖｏｌ％以下であり、特に好ましくは２０Ｖｏｌ％以下である。匣鉢の気孔率が３０Ｖｏｌ％以下であることにより、匣鉢の物理的強度を向上するとともに、保護層との密着性を高め、匣鉢の寿命を延長できる。匣鉢本体１の気孔率は３Ｖｏｌ％以上が好ましく、より好ましくは８Ｖｏｌ％以上であり、さらに好ましくは１３Ｖｏｌ％以上であり、特に好ましくは１５Ｖｏｌ％以上である。匣鉢の気孔率が３Ｖｏｌ％以上であることにより、耐熱衝撃性を高めるとともに、匣鉢を軽量化することができる。 The porosity of the saggar body 2 is preferably 30 Vol% or less, more preferably 26 Vol% or less, further preferably 22 Vol% or less, and particularly preferably 20 Vol% or less. When the porosity of the saggar is 30 Vol% or less, the physical strength of the saggar can be improved, the adhesion with the protective layer can be improved, and the life of the saggar can be extended. The porosity of the saggar body 1 is preferably 3 Vol% or more, more preferably 8 Vol% or more, further preferably 13 Vol% or more, and particularly preferably 15 Vol% or more. When the porosity of the saggar is 3 Vol% or more, the heat impact resistance can be enhanced and the weight of the saggar can be reduced.
　匣鉢本体２のかさ比重は、１．８ｇ／ｃｍ３以上５．０ｇ／ｃｍ３以下であることが好ましく、より好ましくは２．０ｇ／ｃｍ３以上４．８ｇ／ｃｍ３以下であり、さらに好ましくは２．２ｇ／ｃｍ３以上４．６ｇ／ｃｍ３以下である。一般的に、かさ比重が小さいほど熱容量は小さく、耐熱衝撃性も高くなる。匣鉢本体１のかさ比重が１．８ｇ／ｃｍ３以上であることにより匣鉢本体として使用に耐えうる機械的特性を実現できる。匣鉢本体１のかさ比重が４．９ｇ／ｃｍ３以下であることにより、熱容量を下げて電気エネルギーを低減させ、かつ耐熱衝撃性を向上できる。 The bulk specific gravity of the bowl body 2 is preferably 1.8 g / cm 3 or more and 5.0 g / cm 3 or less, more preferably 2.0 g / cm 3 or more and 4.8 g / cm 3 or less, and further. It is preferably 2.2 g / cm 3 or more and 4.6 g / cm 3 or less. Generally, the smaller the bulk specific gravity, the smaller the heat capacity and the higher the thermal shock resistance. When the bulk specific gravity of the saggar body 1 is 1.8 g / cm 3 or more, mechanical characteristics that can withstand use as the saggar body can be realized. When the bulk specific gravity of the saggar body 1 is 4.9 g / cm 3 or less, the heat capacity can be reduced, the electric energy can be reduced, and the thermal shock resistance can be improved.
　匣鉢本体２の熱膨張係数は、０．１×１０－６／℃以上４．８×１０－６／℃以下であることが好ましく、より好ましくは１．５×１０－６／℃以上４．６×１０－６／℃以下であり、さらに好ましくは３．０×１０－６／℃以上４．４×１０－６／℃以下であり、特に好ましくは３．８×１０－６／℃以上４．３×１０－６／℃以下であり、中でも４．１×１０－６／℃以上４．２５×１０－６／℃以下が好ましい。匣鉢本体１の熱膨張係数を前記範囲とすることにより、耐熱衝撃性を向上し、保護層との熱膨張率差に起因する保護層への発生応力を抑制できるため、匣鉢の寿命を延長できる。熱膨張係数はＪＩＳＲ２２０７－２に準拠して室温～１１００℃において測定する。 The coefficient of thermal expansion of the saggar body 2 is preferably 0.1 × 10 -6 / ° C or higher and 4.8 × 10 -6 / ° C or lower, more preferably 1.5 × 10 -6 / ° C or higher 4 It is .6 × 10 -6 / ℃ or less, more preferably 3.0 × 10 -6 / ℃ or more and 4.4 × 10 -6 / ℃ or less, and particularly preferably 3.8 × 10 -6 / ℃. The above is 4.3 × 10 -6 / ° C or lower, and more preferably 4.1 × 10 -6 / ° C or higher and 4.25 × 10 -6 / ° C or lower. By setting the thermal expansion coefficient of the saggar body 1 within the above range, the thermal impact resistance can be improved and the stress generated on the protective layer due to the difference in the coefficient of thermal expansion from the protective layer can be suppressed, so that the life of the saggar can be extended. Can be extended. The coefficient of thermal expansion is measured at room temperature to 1100 ° C. according to JIS R2207-2.
　匣鉢本体２の形状及び寸法は特に限定されるものではなく、リチウムイオン正極材を収容し、焼成できるものであれば、適宜好適な形態を選択できる。 The shape and dimensions of the saggar body 2 are not particularly limited, and a suitable form can be appropriately selected as long as it can accommodate a lithium ion positive electrode material and can be fired.
＜＜保護層＞＞
　保護層３は少なくとも７０質量％以上のＳｎＯ２を含む。保護層３により、リチウムイオン正極材に含まれるリチウムやコバルトと匣鉢本体の構成成分との反応を抑制し、耐食性及び耐熱衝撃性を向上できる。保護層３により、リチウムイオン正極活物質との剥離性を高め、リチウムイオン正極材の回収効率を向上できる。 << Protective layer >>
The protective layer 3 contains at least 70% by mass or more of SnO 2 . The protective layer 3 can suppress the reaction between lithium and cobalt contained in the lithium ion positive electrode material and the constituent components of the saggar body, and can improve corrosion resistance and thermal shock resistance. The protective layer 3 can enhance the releasability from the lithium ion positive electrode active material and improve the recovery efficiency of the lithium ion positive electrode material.
　保護層３におけるＳｎＯ２の含有量は、保護層全体を１００質量％として、好ましくは８０質量％以上、より好ましくは９０質量％以上、特に好ましくは９５質量％以上である。保護層３がＳｎＯ２を７０質量％以上含有することにより、リチウムイオン正極材の焼成時に、該リチウムイオン正極材に含まれるリチウムやコバルトの拡散に対して優れた耐食性を発揮できる。 The content of SnO 2 in the protective layer 3 is preferably 80% by mass or more, more preferably 90% by mass or more, and particularly preferably 95% by mass or more, with the entire protective layer as 100% by mass. When the protective layer 3 contains 70% by mass or more of SnO 2 , it is possible to exhibit excellent corrosion resistance against the diffusion of lithium and cobalt contained in the lithium ion positive electrode material when firing the lithium ion positive electrode material.
　保護層３は、ＺｒＯ２を含有することが好ましい。保護層３にＺｒＯ２を含有することにより、ＳｎＯ２の揮散を抑制できる。保護層３は、ＺｒＯ２に加えて、ＳｉＯ２を含有することが好ましい。ＺｒＯ２に加えて、ＳｉＯ２を含有することにより、揮散開始後の初期の段階から優れたＳｎＯ２の揮散抑制効果を発揮でき、さらに、匣鉢本体と保護層との密着性を高めることができる。 The protective layer 3 preferably contains ZrO 2. By containing ZrO 2 in the protective layer 3, volatilization of SnO 2 can be suppressed. The protective layer 3 preferably contains SiO 2 in addition to ZrO 2. In addition to ZrO 2, by containing SiO 2, it can exhibit excellent volatilization suppressing effect of SnO 2 from the initial stage after the start volatilization, further to enhance the adhesion between the sagger body and the protective layer it can.
　保護層３におけるＳｎＯ２、ＺｒＯ２およびＳｉＯ２の含有量の合量は、好ましくは７０質量％以上であり、より好ましくは８５質量％以上であり、さらに好ましくは９５質量％以上であり、特に好ましくは９８質量％以上である。また、上限は特に限定されないが、典型的には９９．５質量％以下である。ＳｎＯ２、ＺｒＯ２およびＳｉＯ２の含有量の合量が７０質量％以上であることにより、リチウムイオン正極材に含まれるリチウムやコバルトに対する、ＳｎＯ２の優れた耐食性を発揮できる。 The total content of SnO 2 , ZrO 2 and SiO 2 in the protective layer 3 is preferably 70% by mass or more, more preferably 85% by mass or more, still more preferably 95% by mass or more, and in particular. It is preferably 98% by mass or more. The upper limit is not particularly limited, but is typically 99.5% by mass or less. When the total content of SnO 2 , ZrO 2 and SiO 2 is 70% by mass or more, the excellent corrosion resistance of SnO 2 to lithium and cobalt contained in the lithium ion positive electrode material can be exhibited.
　ＳｎＯ２、ＺｒＯ２およびＳｉＯ２の含有量の合量（１００モル％）に対して、ＺｒＯ２およびＳｉＯ２の合量の含有割合が２～５０モル％であることが好ましく、より好ましくは４～３５モル％であり、さらに好ましくは６～２４モル％であり、特に好ましくは８～１５モル％である。 The content ratio of the total amount of ZrO 2 and SiO 2 is preferably 2 to 50 mol%, more preferably 4 with respect to the total content of SnO 2 , ZrO 2 and SiO 2 (100 mol%). It is ~ 35 mol%, more preferably 6-24 mol%, and particularly preferably 8-15 mol%.
　ＳｎＯ２、ＺｒＯ２およびＳｉＯ２の含有量の合量（１００モル％）に対して、ＺｒＯ２およびＳｉＯ２の合量の含有割合が２モル％以上であることにより、ＳｎＯ２の揮散抑制効果が十分に得られる。該含有割合が５０モル％以下であることにより、ＳｎＯ２による耐食性の向上効果が十分に得られる。 When the content ratio of the total amount of ZrO 2 and SiO 2 is 2 mol% or more with respect to the total content of SnO 2 , ZrO 2 and SiO 2 (100 mol%), the effect of suppressing the volatilization of SnO 2 is achieved. Is sufficiently obtained. When the content ratio is 50 mol% or less, the effect of improving the corrosion resistance by SnO 2 can be sufficiently obtained.
　高温場におけるＳｎＯ２の揮散を早期の段階から抑制し、リチウムやコバルトに対するＳｎＯ２の優れた耐食性を発揮する点から、保護層３における、ＳｎＯ２、ＳｉＯ２およびＺｒＯ２の含有量の合量を１００モル％としたとき、ＳｎＯ２を５０～９８モル％、ＳｉＯ２を１～３５モル％、ＺｒＯ２を１～３５モル％含有することが好ましい。 The sum of the contents of SnO 2 , SiO 2 and ZrO 2 in the protective layer 3 from the viewpoint of suppressing the volatilization of SnO 2 in a high temperature field from an early stage and exhibiting the excellent corrosion resistance of SnO 2 against lithium and cobalt. Is 100 mol%, it is preferable that SnO 2 is contained in an amount of 50 to 98 mol%, SiO 2 is contained in an amount of 1 to 35 mol%, and ZrO 2 is contained in an amount of 1 to 35 mol%.
　また、ＳｎＯ２、ＺｒＯ２およびＳｉＯ２の含有量の合量に対して、ＺｒＯ２の含有割合を１モル％以上とすることにより、ＺｒＯ２およびＺｒＳｉＯ４による揮散抑制効果が十分に得られる。また、ＳｉＯ２の含有割合を１モル％以上とすることにより、ＺｒＯ２およびＺｒＳｉＯ４による揮散抑制効果が十分に得られる。 Further, by setting the content ratio of ZrO 2 to 1 mol% or more with respect to the total content of SnO 2 , ZrO 2 and SiO 2 , the effect of suppressing volatilization by ZrO 2 and ZrSiO 4 can be sufficiently obtained. Further, by setting the content ratio of SiO 2 to 1 mol% or more, the effect of suppressing volatilization by ZrO 2 and ZrSiO 4 can be sufficiently obtained.
　さらに、ＳｎＯ２、ＺｒＯ２およびＳｉＯ２の含有量の合量に対して、ＳｉＯ２の含有割合を３５モル％以下とすることにより、ＳｎＯ２による耐食性の向上効果が十分に得られる。 Further, by setting the content ratio of SiO 2 to 35 mol% or less with respect to the total content of SnO 2 , ZrO 2 and SiO 2 , the effect of improving the corrosion resistance by SnO 2 can be sufficiently obtained.
　また、ＳｎＯ２、ＺｒＯ２およびＳｉＯ２の含有量の合量に対して、ＺｒＯ２の含有割合を３５モル％以下とすることにより、ＳｎＯ２による耐食性の向上効果が十分に得られる。 Further, by setting the content ratio of ZrO 2 to 35 mol% or less with respect to the total content of SnO 2 , ZrO 2 and SiO 2 , the effect of improving the corrosion resistance by SnO 2 can be sufficiently obtained.
　ここで、保護層３は、ＳｎＯ２、ＺｒＯ２およびＳｉＯ２の含有量の合量に対して、ＺｒＯ２の含有割合が１～１２モル％の範囲が好ましい。また、ＳｎＯ２、ＺｒＯ２およびＳｉＯ２の含有量の合量に対して、ＳｉＯ２の含有割合も１～１２モル％の範囲が好ましい。したがって、ＳｎＯ２、ＺｒＯ２およびＳｉＯ２の含有量の合量に対して、ＳｎＯ２の含有割合は、７６～９８モル％の範囲が好ましい。 Here, in the protective layer 3, the content ratio of ZrO 2 is preferably in the range of 1 to 12 mol% with respect to the total content of SnO 2 , ZrO 2 and SiO 2. Further, the content ratio of SiO 2 is preferably in the range of 1 to 12 mol% with respect to the total content of SnO 2 , ZrO 2 and SiO 2. Therefore, the content ratio of SnO 2 is preferably in the range of 76 to 98 mol% with respect to the total content of SnO 2 , ZrO 2 and SiO 2.
　ＳｎＯ２、ＺｒＯ２およびＳｉＯ２の含有量の合量に対するＺｒＯ２の含有割合を１～１２モル％とすることにより、ＺｒＯ２を酸化スズ結晶中に実質的に全て固溶させることが可能となり、ＳｎＯ２による耐食性の向上効果が十分に得られる。 By setting the content ratio of ZrO 2 to the total content of SnO 2 , ZrO 2 and SiO 2 to 1 to 12 mol%, it becomes possible to substantially completely dissolve ZrO 2 in the tin oxide crystal. , SnO 2 can sufficiently obtain the effect of improving corrosion resistance.
　ＳｎＯ２、ＺｒＯ２およびＳｉＯ２の含有量の合量に対するＳｉＯ２の含有割合を１～１２モル％とすることにより、ＺｒＯ２およびＺｒＳｉＯ４による揮散抑制効果およびＳｎＯ２による耐食性の向上効果が十分に得られる。さらに、匣鉢本体と保護層との密着性を高めることができる。 By setting the content ratio of SiO 2 to the total content of SnO 2 , ZrO 2 and SiO 2 to 1 to 12 mol%, the effect of suppressing volatilization by ZrO 2 and ZrSiO 4 and the effect of improving corrosion resistance by SnO 2 are sufficient. Obtained in. Further, the adhesion between the saggar body and the protective layer can be improved.
　なお、焼結処理の条件は、一般に、１２００～１６００℃、３～５時間の加熱処理で行われるため、実際に処理する焼結条件によって、耐火組成物中のＳｎＯ２、ＺｒＯ２とＳｉＯ２の配合量を調整すればよい。 Since the conditions for the sintering treatment are generally 1200 to 1600 ° C. for 3 to 5 hours, SnO 2 , ZrO 2 and SiO 2 in the refractory composition depend on the sintering conditions to be actually treated. The blending amount of the above may be adjusted.
　なお、上記の他の成分としては、本発明の耐火物としての特性を損なわないものであれば特に限定されず、酸化スズ質耐火物に使用される公知の成分が挙げられる。 The other components described above are not particularly limited as long as they do not impair the characteristics of the refractory of the present invention, and examples thereof include known components used in tin oxide refractories.
　他の成分としては、例えば、Ａｌ２Ｏ３、ＳｉＯ２、ＣａＯ、ＭｇＯ、Ｌｉ２Ｏ、ＣｕＯ、Ｃｕ２Ｏ、ＺｎＯ、ＨｆＯ２、Ｙ２Ｏ３、ＺｎＯ、Ｍｎ２Ｏ３、ＣｏＯ、ＴｉＯ２、Ｔａ２Ｏ５、ＣｅＯ２、Ｓｂ２Ｏ３、Ｎｂ２Ｏ５、Ｂｉ２Ｏ３、ＵＯ２、ＨｆＯ２などの酸化物が挙げられる。 Other components include, for example, Al 2 O 3 , SiO 2 , CaO, MgO, Li 2 O, CuO, Cu 2 O, ZnO, HfO 2 , Y 2 O 3 , ZnO, Mn 2 O 3 , CoO, TiO. 2 , Ta 2 O 5 , CeO 2 , Sb 2 O 3 , Nb 2 O 5 , Bi 2 O 3 , UO 2 , HfO 2 and other oxides can be mentioned.
　保護層３は、リチウムやコバルトに対する耐食性の点から、Ｆｅを含有しないことが好ましい。保護層３におけるＦｅの含有量は０．５質量％以下であることが好ましく、より好ましくは０．３質量％以下、さらに好ましくは０．０５質量％以下である。 The protective layer 3 preferably does not contain Fe from the viewpoint of corrosion resistance to lithium and cobalt. The Fe content in the protective layer 3 is preferably 0.5% by mass or less, more preferably 0.3% by mass or less, still more preferably 0.05% by mass or less.
　保護層３の熱膨張係数は３．５×１０－６／℃以上５．０×１０－６／℃以下であることが好ましく、より好ましくは３．７×１０－６／℃以上４．７×１０－６／℃以下であり、さらに好ましくは３．９５×１０－６／℃以上４．５×１０－６／℃以下であり、特に好ましくは４．１×１０－６／℃以上４．３×１０－６／℃以下である。保護層３の熱膨張係数を前記範囲とすることにより、耐熱衝撃性を向上するとともに匣鉢本体との密着性を向上できる。 The coefficient of thermal expansion of the protective layer 3 is preferably 3.5 × 10-6 / ° C. or higher and 5.0 × 10-6 / ° C. or lower, more preferably 3.7 × 10-6 / ° C. or higher and 4.7. × 10 -6 / ° C or lower, more preferably 3.95 × 10 -6 / ° C or higher and 4.5 × 10 -6 / ° C or lower, and particularly preferably 4.1 × 10 -6 / ° C or higher 4 .3 x 10-6 / ° C or less. By setting the coefficient of thermal expansion of the protective layer 3 within the above range, the thermal shock resistance can be improved and the adhesion to the saggar body can be improved.
＜リチウムイオン正極材焼成用匣鉢の製造方法＞
　本発明のリチウムイオン正極材焼成用匣鉢の製造方法は、匣鉢本体２を準備する工程、及び匣鉢本体２の正極材と接触する面に保護層３を設ける工程を含む。 <Manufacturing method of pot for firing lithium ion positive electrode material>
The method for manufacturing a pot for firing a lithium ion positive electrode material of the present invention includes a step of preparing a pot body 2 and a step of providing a protective layer 3 on a surface of the pot body 2 in contact with the positive electrode material.
＜＜匣鉢本体を準備する工程＞＞
　匣鉢本体２を準備する手段としては、前記耐火物の原料に対して適量のバインダー材質、水分を加えて混錬後、成形（例えば、フリクションプレス等による加圧成形）、及び乾燥（例えば、自然乾燥）させた後、焼成する。焼成温度及び時間は、適宜設定できる。 << Process of preparing the saggar body >>
As a means for preparing the saggar body 2, an appropriate amount of binder material and water are added to the raw material of the refractory, kneaded, molded (for example, pressure molding by a friction press or the like), and dried (for example, pressure molding by a friction press or the like). After air-drying), it is fired. The firing temperature and time can be set as appropriate.
＜＜保護層を設ける工程＞＞
　保護層３を匣鉢本体２に設ける手段としては、特に限定されず、例えば、コーティング、焼結又は貼り付けが挙げられる。 << Process of providing a protective layer >>
The means for providing the protective layer 3 on the saggar body 2 is not particularly limited, and examples thereof include coating, sintering, and pasting.
（コーティング）
　コーティングにより匣鉢本体２に保護層３を設ける手段としては特に限定されないが、例えば、塗布、スプレーコーティング、溶射による方法が挙げられる。具体的には例えば、少なくとも７０質量％以上のＳｎＯ２を含む材料を純水又はイオン交換水等の溶媒に分散させてスラリーとした後、匣鉢本体２における正極材と接触する面である内面にスプレーコーティングして保護層３を形成させる。その後１２００℃で５時間焼成する。 (coating)
The means for providing the protective layer 3 on the pot body 2 by coating is not particularly limited, and examples thereof include coating, spray coating, and thermal spraying. Specifically, for example, a material containing at least 70% by mass or more of SnO 2 is dispersed in a solvent such as pure water or ion-exchanged water to form a slurry, and then the inner surface of the saggar body 2 that comes into contact with the positive electrode material. Is spray coated to form the protective layer 3. Then it is fired at 1200 ° C. for 5 hours.
　コーティングにより形成する保護層３の厚みは、匣鉢本体２との熱膨張率差による割れを抑制するため、１ｍｍ以下であることが好ましく、より好ましくは８００μｍ以下、より好ましくは５００μｍ以下である。また、耐久性を向上する点から、１μｍ以上であることが好ましく、より好ましくは１０μｍ以上、さらに好ましくは５０μｍ以上、特に好ましくは１００μｍ以上である。 The thickness of the protective layer 3 formed by the coating is preferably 1 mm or less, more preferably 800 μm or less, and more preferably 500 μm or less in order to suppress cracking due to the difference in thermal expansion coefficient from the saggar body 2. Further, from the viewpoint of improving durability, it is preferably 1 μm or more, more preferably 10 μm or more, still more preferably 50 μm or more, and particularly preferably 100 μm or more.
（焼結）　
　焼結により匣鉢本体２に保護層３を設ける手段としては、匣鉢本体２を作製するための焼結時に、保護層３の材料を同時に焼結する方法が挙げられる。具体的には、例えば、匣鉢本体２の材料を匣鉢本体用金型に流しこんだ後、その焼成前に少なくとも７０質量％以上のＳｎＯ２を含む保護層３の材料を流しこみ、匣鉢本体２と保護層３とを同時に焼結する。匣鉢本体２と保護層３とを同時に焼結することで、匣鉢本体２と保護層３とをより強固に固着でき、耐久性を向上できる。 (Sintered)
As a means for providing the protective layer 3 on the saggar main body 2 by sintering, a method of simultaneously sintering the material of the protective layer 3 at the time of sintering for producing the saggar main body 2 can be mentioned. Specifically, for example, after pouring the material of the saggar body 2 into the mold for the saggar body, the material of the protective layer 3 containing at least 70% by mass or more of SnO 2 is poured before firing the saggar. The pot body 2 and the protective layer 3 are sintered at the same time. By simultaneously sintering the saggar body 2 and the protective layer 3, the saggar body 2 and the protective layer 3 can be more firmly fixed to each other, and the durability can be improved.
　コーティングや焼結により保護層３を形成する場合、保護層３の材料は、ＳｎＯ２に加えてＺｒＳｉＯ４を含有することが好ましい。ＳｎＯ２に加えてＺｒＳｉＯ４を含有する材料を焼結することにより、ＳｉＯ２が発生するとともにＳｎＯ２中にＺｒＯ２中が固溶した状態となる。このことにより保護層を形成する粒子同士がＳｉＯ２でボンディングされるとともに、匣鉢本体と保護層の密着性がより強固となる。固溶限界を超えるＺｒＳｉＯ４を含有させた場合には未反応分としてＺｒＳｉＯ４が残る。このことにより、保護層を形成する粒子同士がＳｉＯ２およびＺｒＳｉＯ４でボンディングされるとともに、匣鉢本体と保護層の密着性がより強固となる。またＳｉＯ２および／またはＺｒＳｉＯ４がＳｎＯ２の粒界に存在することにより、ＳｎＯ２の揮散が効果的に抑制できる。 When the protective layer 3 is formed by coating or sintering, the material of the protective layer 3 preferably contains ZrSiO 4 in addition to SnO 2. By sintering the material containing ZrSiO 4 in addition to SnO 2 , SiO 2 is generated and ZrO 2 is in a solid solution state in SnO 2. As a result, the particles forming the protective layer are bonded to each other by SiO 2 , and the adhesion between the saggar body and the protective layer becomes stronger. When ZrSiO 4 exceeding the solid solution limit is contained, ZrSiO 4 remains as an unreacted component. As a result, the particles forming the protective layer are bonded to each other at SiO 2 and ZrSiO 4 , and the adhesion between the saggar body and the protective layer becomes stronger. Also by SiO 2 and / or ZrSiO 4 are present in the grain boundary of the SnO 2, volatilization of SnO 2 can be effectively suppressed.
　焼結により形成する保護層３の厚みは、１０ｍｍ以下であることが好ましく、より好ましくは５ｍｍ以下である。コスト及び質量を抑える点から、３ｍｍ以下であることが特に好ましい。 The thickness of the protective layer 3 formed by sintering is preferably 10 mm or less, more preferably 5 mm or less. It is particularly preferably 3 mm or less from the viewpoint of suppressing cost and mass.
　保護層３の材料に含まれるＳｎＯ２は、粒子として適用されるのが好ましく、その粒子の粒子径は、例えば最大粒子径を１～３ｍｍとし、粗粒、中粒、細粒、微粒と粒径の異なる粒子を組み合わせて適宜調整するのが好ましい。また、保護層３の耐久性の付与を目的として、前記の粗粒、中粒、細粒、微粒に加え、例えば粒径３～５０μｍのＳｎＯ２を組み合わせてもよい。 SnO 2 contained in the material of the protective layer 3 is preferably applied as particles, and the particle size of the particles is, for example, a maximum particle size of 1 to 3 mm, and coarse particles, medium particles, fine particles, fine particles and particles. It is preferable to combine particles having different diameters and adjust appropriately. Further, for the purpose of imparting durability to the protective layer 3, in addition to the above-mentioned coarse particles, medium particles, fine particles, and fine particles, for example, SnO 2 having a particle size of 3 to 50 μm may be combined.
　ここで、例えば、粗粒は１７００μｍ未満８４０μｍ以上、中粒は８４０μｍ未満２５０μｍ以上、細粒は２５０μｍ未満７５μｍ以上、微粒は７５μｍ未満１５μｍ以上、とした場合、これら４種の粒子を含む材をそれぞれ調整して配合する。これら４種の骨材についてのみ説明すれば、これらを１００質量％としたとき、粗粒を２１～３３質量％、中粒を１５～２８質量％、細粒を３０～４５質量％、微粒を５～１８質量％、の範囲となる含有割合が坏土の充填の点で好ましい。また、例えば、ＳｎＯ２を５０μｍ以下の粒子で構成してもよく、保護層３の厚みを１ｍｍ以下に設定できる。 Here, for example, when coarse particles are less than 1700 μm and 840 μm or more, medium particles are less than 840 μm and 250 μm or more, fine particles are less than 250 μm and 75 μm or more, and fine particles are less than 75 μm and 15 μm or more, materials containing these four types of particles are used. Adjust and mix. Explaining only these four types of aggregates, when these are 100% by mass, coarse grains are 21 to 33% by mass, medium grains are 15 to 28% by mass, fine grains are 30 to 45% by mass, and fine grains are. A content ratio in the range of 5 to 18% by mass is preferable in terms of filling the clay. Further, for example, SnO 2 may be composed of particles of 50 μm or less, and the thickness of the protective layer 3 can be set to 1 mm or less.
　本明細書において、粒度は、ＪＩＳ　Ｒ２５５２（１９７７年）に準じて測定された値をいう。ＳｎＯ２は、耐火物使用後品、耐火物廃材等を粉砕し、粒径を調整したものを使用してもよい。 In the present specification, the particle size refers to a value measured according to JIS R2552 (1977). As SnO 2 , a product after using a refractory material, a waste material of a refractory material, or the like may be crushed to adjust the particle size.
（貼り付け）
　貼り付けにより匣鉢本体２に保護層３を設ける手段としては、例えば、匣鉢本体２の保護層３の形成面に接着材層を形成した後、保護層３を前記接着材層に押し付けて一体化する。接着材としては、例えば、ガラス、アルミナ系接着剤、ジルコニア系接着剤、シリコンなどの金属が挙げられる。具体的には例えば、接着材がガラスである場合は、匣鉢本体２の保護層３の形成面にガラスの微粒子を含む接着材層を形成した後、該ガラスを焼き付けて溶融させることにより保護層３と匣鉢本体２とを一体化する。接着材層の厚みは、通常５～５００μｍであることが好ましく、より好ましくは１０～２００μｍである。 (pasting)
As a means for providing the protective layer 3 on the saggar main body 2 by sticking, for example, after forming an adhesive layer on the forming surface of the protective layer 3 of the saggar main body 2, the protective layer 3 is pressed against the adhesive layer. Integrate. Examples of the adhesive include glass, alumina-based adhesives, zirconia-based adhesives, and metals such as silicon. Specifically, for example, when the adhesive is glass, it is protected by forming an adhesive layer containing fine particles of glass on the forming surface of the protective layer 3 of the saggar body 2 and then baking and melting the glass. The layer 3 and the saggar body 2 are integrated. The thickness of the adhesive layer is usually preferably 5 to 500 μm, more preferably 10 to 200 μm.
　貼り付けにより保護層３を形成する場合、保護層３の厚みは、１０ｍｍ以下であることが好ましく、より好ましくは５ｍｍ以下である。コスト及び質量を抑える点から、３ｍｍ以下であることが特に好ましく、１ｍｍ以下であることが中でも好ましい。 When the protective layer 3 is formed by sticking, the thickness of the protective layer 3 is preferably 10 mm or less, more preferably 5 mm or less. From the viewpoint of suppressing cost and mass, it is particularly preferably 3 mm or less, and particularly preferably 1 mm or less.
　上記のようにして製造されたリチウムイオン正極材焼成用匣鉢は、少なくとも７０質量％以上のＳｎＯ２を含有する保護層３により匣鉢本体２の正極材と接触する面が被覆されている。該保護層３により、リチウムイオン正極材に含まれるリチウムやコバルトと匣鉢本体２の構成成分との反応が抑制され、耐食性及び耐熱衝撃性に優れたリチウムイオン正極材焼成用匣鉢となる。 In the lithium-ion positive electrode material firing pot produced as described above, the surface of the pot body 2 in contact with the positive electrode material is covered with a protective layer 3 containing at least 70% by mass or more of SnO 2. The protective layer 3 suppresses the reaction between lithium and cobalt contained in the lithium ion positive electrode material and the constituent components of the pot body 2, so that the lithium ion positive electrode material firing pot has excellent corrosion resistance and thermal shock resistance.
　以下、本発明を実施例及び比較例によって具体的に説明するが、本発明はこれらの記載によって何ら限定して解釈されるものではない。 Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not construed as being limited by these descriptions.
（匣鉢本体基板の作製：例１～２０、２５～２７）
　表１に示す組成となるように匣鉢本体の原料を混合し、匣鉢用金型に充填し、フリクションプレスを用いて成型圧４４ＭＰａにて加圧成形して、焼成後の寸法及び外形が匣鉢本体の寸法及び外形が１５０ｍｍ×１５０ｍｍ×１０ｍｍ（高さ）の板状となるように成形した。次に、自然乾燥工程、端面仕上げ工程を経て、成型物を焼成炉で焼成し、匣鉢本体基板を得た。例１～５は匣鉢本体基板に保護層を形成しなかった比較例である。 (Preparation of Saggar Body Substrate: Examples 1-20, 25-27)
The raw materials of the saggar body are mixed so as to have the composition shown in Table 1, filled in a saggar mold, and pressure-molded at a molding pressure of 44 MPa using a friction press to obtain the dimensions and outer shape after firing. The saggar body was molded so as to have a plate shape having a size and an outer shape of 150 mm × 150 mm × 10 mm (height). Next, the molded product was fired in a firing furnace through a natural drying step and an end face finishing step to obtain a saggar body substrate. Examples 1 to 5 are comparative examples in which the protective layer was not formed on the saggar body substrate.
　得られた匣鉢本体基板について気孔率、密度、熱膨張係数を測定した。気孔率はＪＩＳＲ２２０５（１９９２年）に準拠して測定した。熱膨張係数はＪＩＳＲ２２０７－２（２００７）に準拠して室温～１１００℃において測定した。かさ密度および気孔率はＪＩＳＲ２２０５（１９９２年）により測定した。 The porosity, density, and coefficient of thermal expansion of the obtained saggar body substrate were measured. Porosity was measured according to JIS R2205 (1992). The coefficient of thermal expansion was measured at room temperature to 1100 ° C. according to JIS R2207-2 (2007). Bulk density and porosity were measured by JIS R2205 (1992).
（スプレーコーティングによる保護層の形成：例６～８、１２～２０、２６及び２７）
　上記のようにして得られた匣鉢本体基板に、表１に示す組成となるように調整した保護層の材料をアネスト岩田コーティングソリューションズ社製ＷＡ－２００－２５１ＺＰを用いて吹付空気圧力０．３４ＭＰａでスプレーコーティングし、保護層を形成した。 (Formation of protective layer by spray coating: Examples 6-8, 12-20, 26 and 27)
A protective layer material adjusted to have the composition shown in Table 1 was sprayed onto the pot body substrate obtained as described above using WA-200-251ZP manufactured by Anest Iwata Coating Solutions Co., Ltd., and the air pressure was 0.34 MPa. Spray coated with to form a protective layer.
　例６～８、１５～２０、２６及び２７における保護層におけるＳｎＯ２としては、粒径及び比率が、０．０５ｍｍが４５質量％、０．０１ｍｍが２０質量％、０．００３ｍｍが１３質量％、０．０００８７ｍｍが２２質量％であるものを用いた。例１２～１４における保護層におけるＳｎＯ２としては、粒径が０．００３ｍｍであるものを用いた。 As SnO 2 in the protective layer in Examples 6 to 8, 15 to 20, 26 and 27, the particle size and ratio are 45% by mass for 0.05 mm, 20% by mass for 0.01 mm, and 13% by mass for 0.003 mm. , 0.00087 mm is 22% by mass. As SnO 2 in the protective layer in Examples 12 to 14, those having a particle size of 0.003 mm were used.
（貼り付けによる保護層の形成：例９～１１及び２５）
　上記のようにして得られた匣鉢本体基板に、ＳｉＯ２を６７質量％、Ａｌ２Ｏ３を１２質量％、Ｂ２Ｏ３を７質量％、ＭｇＯを５質量％、ＣａＯを４．５質量％、ＳｒＯを４．５質量％含有する接着材層を形成し、１１５０℃にて該接着材層を焼き付けた後、表１に示す組成の保護層を該接着材層に０．３ＭＰａの圧力にて１分間押し付けて一体化した。 (Formation of protective layer by pasting: Examples 9-11 and 25)
In the pot body substrate obtained as described above, SiO 2 is 67% by mass, Al 2 O 3 is 12% by mass, B 2 O 3 is 7% by mass, MgO is 5% by mass, and CaO is 4.5. An adhesive layer containing 4.5% by mass and 4.5% by mass of SrO was formed, and the adhesive layer was baked at 1150 ° C., and then a protective layer having the composition shown in Table 1 was applied to the adhesive layer at 0.3 MPa. It was integrated by pressing with pressure for 1 minute.
（焼結による保護層の形成：例２１～２４）
　表１に示す組成となるように匣鉢本体の原料を混合し、匣鉢用金型に充填した後、表１に示す組成の保護層の原料を匣鉢本体の内側に充填した。フリクションプレスを用いて成型圧４４ＭＰａにて加圧成形して、焼成後の匣鉢本体の寸法及び外形が１５０ｍｍ×１５０ｍｍ×１０ｍｍ（高さ）の板状となるように成形した。次に、自然乾燥工程、端面仕上げ工程を経て、成型物を焼成炉で焼成し、匣鉢本体基板に保護層を形成した。 (Formation of protective layer by sintering: Examples 21 to 24)
The raw materials of the saggar body were mixed so as to have the composition shown in Table 1, and the saggar mold was filled, and then the raw material of the protective layer having the composition shown in Table 1 was filled inside the saggar body. It was pressure-molded at a molding pressure of 44 MPa using a friction press, and molded so that the dimensions and outer shape of the pot body after firing were 150 mm × 150 mm × 10 mm (height). Next, after undergoing a natural drying step and an end face finishing step, the molded product was fired in a firing furnace to form a protective layer on the main body substrate of the saggar.
　例２１～２４の保護層におけるＳｎＯ２としては、粒径及び比率が、１．７ｍｍが２７質量％、０．６８ｍｍが２２質量、０．２４ｍｍが３５質量％、０．００３ｍｍが１６質量％であるものを用いた。 As SnO 2 in the protective layer of Examples 21 to 24, the particle size and ratio are 27% by mass for 1.7 mm, 22% by mass for 0.68 mm, 35% by mass for 0.24 mm, and 16% by mass for 0.003 mm. Something was used.
　上記のようにして形成した保護層の厚みを測定した。気孔率、かさ密度、熱膨張係数は、保護層厚みが５ｍｍとなるサンプルを作製し、保護層から切り出し加工した測定用サンプルを用いて測定した。気孔率はＪＩＳＲ２２０５（１９９２年）に準拠して測定した。熱膨張係数はＪＩＳＲ２２０７－２（２００７）に準拠して室温～１１００℃において測定した。 The thickness of the protective layer formed as described above was measured. The porosity, bulk density, and coefficient of thermal expansion were measured by preparing a sample having a protective layer thickness of 5 mm and using a measurement sample cut out from the protective layer. Porosity was measured according to JIS R2205 (1992). The coefficient of thermal expansion was measured at room temperature to 1100 ° C. according to JIS R2207-2 (2007).
＜リチウムイオン正極材の焼成＞
　上記のようにして作製した基板にリチウムイオン正極材１５ｇ（炭酸リチウム１０ｇ、酸化コバルト５ｇ）を直径５０ｍｍの面積となるようにタッピングした。１０５０℃まで４時間かけて昇温後、１０時間保持し、６時間かけて常温に降温させた。 <Sintering of lithium ion positive electrode material>
The substrate prepared as described above was tapped with 15 g of a lithium ion positive electrode material (10 g of lithium carbonate and 5 g of cobalt oxide) so as to have an area of 50 mm in diameter. After raising the temperature to 1050 ° C. over 4 hours, the temperature was maintained for 10 hours, and the temperature was lowered to room temperature over 6 hours.
（付着量の測定）
　付着量の測定は、リチウムイオン正極材焼成後に基板を裏返し、５秒静止させた後のリチウムイオン正極材の付着量を測定した。 (Measurement of adhesion amount)
The amount of adhesion was measured by turning the substrate over after firing the lithium ion positive electrode material and allowing it to stand still for 5 seconds, and then measuring the amount of adhesion of the lithium ion positive electrode material.
（最高使用回数の測定）
　１５０×１５０×１０ｍｍの板を用い、リチウムイオン正極材の焼成について繰り返し反応試験を実施した。なお、固着したリチウムイオン正極材はヘラで剥がし取った。１０５０℃まで４時間かけて昇温後、１０時間保持し、１０５０℃から大気中で一気に冷却した。匣鉢本体基板にクラックが生じるか、保護層が剥がれて匣鉢本体基板にリチウムイオン正極材が混入した時点を最高使用回数とし、５０回に到達した時点で終了した。 (Measurement of maximum number of uses)
Using a plate of 150 × 150 × 10 mm, a reaction test was repeatedly carried out for firing the lithium ion positive electrode material. The fixed lithium ion positive electrode material was peeled off with a spatula. The temperature was raised to 1050 ° C. over 4 hours, held for 10 hours, and cooled from 1050 ° C. in the air at once. The maximum number of times of use was defined as when the saggar body substrate was cracked or the protective layer was peeled off and the lithium ion positive electrode material was mixed in the saggar body substrate, and the process was terminated when the number of times of use reached 50.
　結果を表１～３に示す。また、例１、３、４及び５について、リチウムイオン正極材の焼成後における匣鉢の表面を示す図を、それぞれ図２～５に示す。また、図６（ａ）及び（ｂ）は、例１０と同様の保護層の組成からなる基板（厚み２０ｍｍ）にリチウムイオン正極材を焼結した結果を示す。例１～５、７及び８は比較例、例６、９～２７は実施例である。 The results are shown in Tables 1 to 3. Further, with respect to Examples 1, 3, 4 and 5, the figures showing the surface of the bowl after firing the lithium ion positive electrode material are shown in FIGS. 2 to 5, respectively. Further, FIGS. 6A and 6B show the results of sintering a lithium ion positive electrode material on a substrate (thickness 20 mm) having the same protective layer composition as in Example 10. Examples 1 to 5, 7 and 8 are comparative examples, and examples 6, 9 to 27 are examples.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　表１～３に示すように、実施例は匣鉢本体の正極材と接触する面を被覆する少なくとも７０質量％以上のＳｎＯ２を含む保護層を設けたことにより、比較例に対して、正極活物質との剥離性が良好であり、耐食性及び耐熱衝撃性に優れていた。また、コーティングにより保護層を形成した例６及び例１２の結果から、コーティングにより保護層を形成する場合は、保護層の厚みは、匣鉢本体との熱膨張率差による割れを抑制するため、１ｍｍ以下であることが好ましいことがわかった。 As shown in Tables 1 to 3, in the examples, a protective layer containing at least 70% by mass or more of SnO 2 was provided to cover the surface of the saggar body in contact with the positive electrode material. It had good releasability from the active material, and was excellent in corrosion resistance and thermal shock resistance. Further, from the results of Examples 6 and 12 in which the protective layer was formed by the coating, when the protective layer was formed by the coating, the thickness of the protective layer suppressed cracking due to the difference in the coefficient of thermal expansion from the saggar body. It was found that it is preferably 1 mm or less.
　また、図６（ａ）及び（ｂ）に示すように、少なくとも７０質量％以上のＳｎＯ２を含む基板上でリチウムイオン正極材を焼結した結果、該基板におけるリチウムイオン正極材との接触面にリチウムイオン正極材は全く接着しておらず、傾斜させたところ自重で滑り落ち、反応層の形成もほぼ観察されなかった。これに対し、少なくとも７０質量％以上のＳｎＯ２を含む保護層を形成しない基板上でリチウムイオン正極材を焼結した結果が図２～５である。図２においては、該基板におけるリチウムイオン正極材との接触面全体が茶褐色に変色し、基板から浮き出してきた褐色生成物層が観察された。また、図３～５では、リチウムイオン正極材焼成後の該接触面にはＬＣＯ層が形成され、該基板に強固に固着していた。 Further, as shown in FIGS. 6A and 6B, as a result of sintering the lithium ion positive electrode material on the substrate containing at least 70% by mass or more of SnO 2, the contact surface of the substrate with the lithium ion positive electrode material. The lithium ion positive electrode material was not adhered at all, and when it was tilted, it slipped off due to its own weight, and the formation of a reaction layer was hardly observed. On the other hand, FIGS. 2 to 5 show the results of sintering the lithium ion positive electrode material on a substrate that does not form a protective layer containing at least 70% by mass or more of SnO 2. In FIG. 2, the entire contact surface of the substrate with the lithium ion positive electrode material was discolored to brown, and a brown product layer emerging from the substrate was observed. Further, in FIGS. 3 to 5, an LCO layer was formed on the contact surface after firing the lithium ion positive electrode material, and was firmly adhered to the substrate.
　本発明を特定の態様を参照して詳細に説明したが、本発明の精神と範囲を離れることなく様々な変更および修正が可能であることは、当業者にとって明らかである。なお、本出願は、２０１９年１１月８日付けで出願された日本特許出願（特願２０１９－２０３４８６）に基づいており、その全体が引用により援用される。また、ここに引用されるすべての参照は全体として取り込まれる。 Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various modifications and modifications can be made without departing from the spirit and scope of the invention. This application is based on a Japanese patent application (Japanese Patent Application No. 2019-203486) filed on November 8, 2019, and the entire application is incorporated by reference. Also, all references cited here are taken in as a whole.
１　リチウムイオン正極材焼成用匣鉢
２　匣鉢本体
２１１　底部
２１２　壁面
２１　内側表面
３　保護層 1 Lithium-ion positive electrode material firing saggar 2 saggar body 211 bottom 212 wall surface 21 inner surface 3 protective layer

Claims (11)

  1. 　匣鉢本体と、前記匣鉢本体の表面を被覆する保護層と、を備える匣鉢であって、
    　前記保護層は少なくとも７０質量％以上のＳｎＯ２を含む、匣鉢。     A saggar that includes a saggar body and a protective layer that covers the surface of the saggar body.
    The protective layer is a saggar containing at least 70% by mass or more of SnO 2.
  2. 　匣鉢本体と、前記匣鉢本体のリチウムイオン正極材と接触する面を被覆する保護層と、を備えるリチウムイオン正極材焼成用匣鉢であって、
    　前記保護層は少なくとも７０質量％以上のＳｎＯ２を含む、匣鉢。     A pot for firing a lithium ion positive electrode material, comprising a pot body and a protective layer covering a surface of the pot body that comes into contact with the lithium ion positive electrode material.
    The protective layer is a saggar containing at least 70% by mass or more of SnO 2.
  3. 　前記保護層がＺｒＯ２を含む、請求項１または２に記載の匣鉢。 The saggar according to claim 1 or 2, wherein the protective layer contains ZrO 2.
  4. 　前記保護層がＳｉＯ２を含む、請求項１～３のいずれか１項に記載の匣鉢。 The saggar according to any one of claims 1 to 3, wherein the protective layer contains SiO 2.
  5. 　前記保護層におけるＳｎＯ２、ＺｒＯ２およびＳｉＯ２の含有量の合量に対して、ＺｒＯ２およびＳｉＯ２の合量の含有割合が２～５０モル％である、請求項１～４のいずれか１項に記載の匣鉢。 Any of claims 1 to 4, wherein the content ratio of the total amount of ZrO 2 and SiO 2 is 2 to 50 mol% with respect to the total content of SnO 2 , ZrO 2 and SiO 2 in the protective layer. The bowl according to item 1.
  6. 　前記匣鉢本体がジルコン質不定形耐火物からなる請求項１～５のいずれか１項に記載の匣鉢。 The saggar according to any one of claims 1 to 5, wherein the saggar body is made of a zircon amorphous refractory.
  7. 　前記匣鉢本体の気孔率が３０Ｖｏｌ％以下である、請求項１～６のいずれか１項に記載の匣鉢。 The bowl according to any one of claims 1 to 6, wherein the porosity of the bowl body is 30 Vol% or less.
  8. 　前記匣鉢本体のかさ比重が１．８ｇ／ｃｍ３以上５．０ｇ／ｃｍ３以下である、請求項１～７のいずれか１項に記載の匣鉢。 The saggar according to any one of claims 1 to 7, wherein the saggar body has a bulk specific gravity of 1.8 g / cm 3 or more and 5.0 g / cm 3 or less.
  9. 　前記匣鉢本体の熱膨張係数が０．１×１０－６／℃以上４．８×１０－６／℃以下である、請求項１～８のいずれか１項に記載の匣鉢。 The bowl according to any one of claims 1 to 8, wherein the coefficient of thermal expansion of the bowl body is 0.1 × 10 -6 / ° C or higher and 4.8 × 10 -6 / ° C or lower.
  10. 　前記保護層の熱膨張係数が３．５×１０－６／℃以上５．０×１０－６／℃以下である、請求項１～９のいずれか１項に記載の匣鉢。 The saggar according to any one of claims 1 to 9, wherein the coefficient of thermal expansion of the protective layer is 3.5 × 10 -6 / ° C. or higher and 5.0 × 10 -6 / ° C. or lower.
  11. 　匣鉢本体を準備し、前記匣鉢本体のリチウムイオン正極材と接触する面に保護層を設けることを含むリチウムイオン正極材焼成用匣鉢の製造方法であって、
    　前記保護層が少なくとも７０質量％以上のＳｎＯ２を含むリチウムイオン正極材焼成用匣鉢の製造方法。     A method for producing a lithium-ion positive electrode material firing sack, which comprises preparing a sack body and providing a protective layer on the surface of the sack body that comes into contact with the lithium-ion positive electrode material.
    A method for producing a saggar for firing a lithium ion positive electrode material, wherein the protective layer contains at least 70% by mass or more of SnO 2.
PCT/JP2020/040934 2019-11-08 2020-10-30 Sagger and method for producing same WO2021090778A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010281471A (en) * 2009-06-02 2010-12-16 Maruei Sangyo Gousakusha Co Ltd Corrosion-resistant burning tool and method of manufacturing the same
JP2014228239A (en) * 2013-05-24 2014-12-08 東京窯業株式会社 Heat treatment vessel
JP2019121601A (en) * 2018-01-08 2019-07-22 朱 性宇Ｘｉｎｇｙｕ Ｚｈｕ Lithium ion battery electrode material firing pot and protective layer of the same

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010281471A (en) * 2009-06-02 2010-12-16 Maruei Sangyo Gousakusha Co Ltd Corrosion-resistant burning tool and method of manufacturing the same
JP2014228239A (en) * 2013-05-24 2014-12-08 東京窯業株式会社 Heat treatment vessel
JP2019121601A (en) * 2018-01-08 2019-07-22 朱 性宇Ｘｉｎｇｙｕ Ｚｈｕ Lithium ion battery electrode material firing pot and protective layer of the same

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